Winter sunshine is not strong, but it does not mean that the uv is not strong. The air in this season is so dry and thin that ultraviolet penetration is strengthened, so it is more lethal for our eyes. Thus you need to wear sunglasses in winter.
Sunglasses don't just exist as an accessory; their main function is sun protection and eye protection. The sunshine in winter is still strong so iti is necessary to wear sunglasses.
When it snows in winter, it is neceaasry for us to equip with protective sunglasses that can filter ultraviolet light, which can prevent snow blindness.